Nanoscale imaging of the electronic and structural transitions in vanadium dioxide

We investigate the electronic and structural changes at the nanoscale in vanadium dioxide (VO₂) in the vicinity of its thermally driven phase transition. Both electronic and structural changes exhibit phase coexistence leading to percolation. In addition, we observe a dichotomy between the local electronic and structural transitions. Nanoscale x-ray diffraction reveals local, nonmonotonic switching of the lattice structure, a phenomenon that is not seen in the electronic insulator-to-metal transition mapped by near-field infrared microscopy.